Example 1: Bathymetry

[jachym]

In order to develop a Bathymetry Map, you need to download two layers.
One with an object layer for lakes and the other with depth layer. For this
purpose, you can use both QGIS and GrassGIS. Algorithms will convert the
available raster to the form of isolines. In the properties of the layer, specify
the extent of the layer information. You can use the lake layer as a base layer.

[jachym]

I suggest, you simply download the global bathymetry map from https://www.gebco.net/data_and_products/gridded_bathymetry_data/

1. Under the global map, click at "GEBCO_2014 Grid (30 arc-second interval)"
2. In the table, use "Global grid 1D netCDF"
3. Under the table, click "Add data to basket"
4. "View the basket"
5. In the new "basket page" you should click at "Checkout the basket"
6. You will have to register yourself into the system
7. You should be able to download the data to your system and publish it as WMS and WCS

You may also be able to register the WMS layer from https://www.gebco.net/data_and_products/gebco_web_services/web_map_service/ and register it to the platform

The difference between the WMS and the data itself is, that the WMS does not offer real data, just shaded image map.

There are no data from big lakes unfortunately, but I'm not aware of any data, where you can get information about lake depth :-(